Tappet



Oct. 26, 1943- J. A. NAHLINGE R TAPPEI Filed Jan. 15, 1942 INVENTOR.JOHN A. NAHLINGER BY ATTORNEYS.

72% AMZaMW/M.

Patented Oct. 26, 1943 UNITED STATES PATENT OFFICE- TAPPET John A.Nahlinger, Cleveland, Ohio Application January 15, 1942, Serial No.426,877 6 Claims. (01. 123- 90) This invention relates, as indicated, tovalve tappet adjusting means, but has reference more particularly tomeans for retaining the tappet screw in adjusted position.

Originally the tappet screw was locked in adjusted position relativelyto the stem of the tappet to which such screw was threaded, by means ofan ordinary bolt the end faces of which were radial and the axial facesof which were adapted to be engaged by a wrench. One of the radial facesof the nut was jammed against the stem and locked the latter to thescrew. Such 'locking means are subject to the following objections:

1. Each adjustment of the screw requires loosening and tightening of thenut;

2. It is difllcult to hold the screw in the exact position desired whilejamming the nut;

3. The nut and the head of the screw are so close together andinconveniently located in a motor that they are apt to be confused, and

4. Two wrenches, one for the nut and one for the screw head, andconsequently two hands are simultaneously required to accomplish thedifllcultly attained precise adjustment.

The market then tions be overcome and the result was a spring whichdragged between the screw and thestem. The structure required to utilizesuch a spring is complicated, bulky and costly to manufacture. My stepforward in the tappet art is the elimination of such complications,bulkiness, and costliness. I do not use a spring and yet a tappet havingincorporated therein my adjusting means requires manipulation of onlythe screw 'and has retained adjustment under severe actual test.

A primary object of the invention is to provide means for adjusting thetappet length so as to vary the clearance between the tappet and valvestem in combination with means for effectively maintaining the tappet inadjusted position.

Another object of the invention is to provide valve tappet adjustingmeans which can be manipulated with one hand, leaving the other handfree for the use of a tappet clearance gauge or the like.

A further object of the invention is to provide means for concealing thetappet adjustment retaining means so as to prevent unauthorized,accidental, or unskilled adjustment of said retaining means.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

demanded that these obleclarged lower end 8 In the accompanying drawing,forming a part of this specification, and in which like numerals areemployed to designate like parts throughout the'same:

Fig. 1 is a view, in elevation, showing a invention;

Fig. 2 is a fragmentary cross-section taken on theline 2-2 of Fig. l,and

Fig. 3 is a detail elevation of the tappet screw, lock-nut and cover.

In the drawing, reference numeral l designates the cylinder block of aninternal combustion engine provided with the usual poppet valve 2engageable with a valve seat 3 and having its stem 4 slidably mounted inthe block and urged to valve closing position by the usual surroundingvalve spring 5 bearing on a valve washer 6 which is secured to the valvestem.

A tappet member or sleeve 1 is slidably mounted in the cylinder blockbelow and in axial alignment with the valve stem and has the usualenperiodically lifted by a cam in to thereby actuate the partly insection and partly tappet embodying the 9 on a cam .shaft valve.

The stem of the tappet member 1 has a threaded recess, the threads ofwhich are engaged by a tappet screw II which is provided with a head l2.This head has fiat sides whereby the screw may be engaged by a wrench tothereby move the screw axially with respect to the member I so as toadjust or vary the clearance between the head I! and the lower end ofthe stem 4 in accordance with well-recognized practice.

My means for retaining the tappet screw in adjusted position comprises anut l3 having fiat sides similar to those on the head 12 so as to beengageable by the same wrench as that used for turning the screw H. Thenut I3 is in threaded engagement with the screw II and has a stemportion l4 presenting a conical outer surface l5 which is adapted toengage a similar surface It forming the outer wall of a counterbore inthe upper end of the recess of the tappet sleeve 1.

Although the surfaces l5 and iii are both shown as conical, it will beunderstood that only one need be conical. The thickness of the lowerpart of the wall of the stem portion I4 is relatively slight wherebywhen the nut is screwed downwardly, the action of the surfaces l5 and I6wedges or squeezes such lower'part into intimate engagement with thescrew H and thus acts as a brake. For best results the surfaces i5 andI6 and the shoulder at the upper end of the nut are so related that whensuch shoulder rests against the top of the tappet stem, the wedgins orsqueezing action does not constitute a dead brake and freeze the screwto the tappet stem because such braking and freezing would be open tothe objections above enumerated. When In order to insure againstaccidentally disturb ing the nut after it has been once set, I cover itwith a snugly fitting cap IT. The fit is such that a screwdriver or thelike can easily pry the cap oil, but motor vibrations will beineffective. The cap alsov conceals the nut from unskilled workmen, who,after discovering thenut, will then be warned against disturbingthesame.

After the original positioning of the nut, it need not be moved. Thus,when it is desired to adjust the clearance between the head P2 of thescrew Ii and the lower end of the valve stem, the nut remains concealedand protected by the cap while the screw is turned in either directionfor adjusting purposes. I wish to stress that the clearance may beincreased or decreased with equal facility while the nutremainsundisturbed and that the effectiveness of the nut is constantnotwithstanding manual manipulation of the screw. 7

It will be obvious to those skilled in the art that my tappet iseconomical .to manufacture, structurally simple, and very compact.

, It thus appears that a highly eil'ective tappet adjustment has beenprovided, which adjustment can be effected by means of a single wrench,leaving one hand free for the use ofa tappet clear- 8110B gauge.

It is to be understood that the form of my invention, herewith shown anddescribed, is to be taken as a preferred example of thesame, and

that various changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of my invention, or thescope ofthe subjoined claims.

Having thus described myinvention, I claim:

1. In combination, a poppet valve, a tappet unit comprising a tappetsleeve and a tappet screw axially adjustable relatively to said sleeve,and means for exerting a clamping action on said screw to'lock itin'adiusted position, said means comprising a, nut threadedly secured tosaid screw, said nut having a tapered stem engageable with saldsleeve.

having a counterbore in its upper end, and a tappet screw axiallyadjustable relatively to said sleeve, and means for exerting a clampingaction on said screw to lock it in adjusted position, said meanscomprising a nut in threaded engagement with said screw and having astem, the surface of which is in engagement with the surface of said gocounterbore, one of. said surfaces being conical,

whereby, upon relative movement of said nut towards said sleeve,saidstem grips said screw sufiiciently to prevent disturbance of thescrew due to motor vibrations, but not sufficiently to preby means, ofa

vent adjustment of the screw wrench.

4. In combination, a poppet valve, a tappet unit comprising a tappetsleeve and a nut .for locking said screw in tirely from view, said meansbeing movable relatively to said sleeve. r a

/ 5. In combination, a poppet valve, a tappet unit comprising afltappetsleeve and a tappet screw, a nut for. locking saidscrew inadjustedposition,

and a cap loosely mounted on said nut and having a skirt portion adaptedto entirely conceal the nut from view, said nut. Y 40 6. In combination,a poppet valve, a tappet unit comprising an 'interiorly threaded tappetsleeve having a counterbore in its upper end, and a tappet screw axiallyadjustable relatively to said and meansfor exerting aclamping action onsaid screw to lock it in adjusted position, said sleeve,

meanscomprising a nut in threaded engagement with said screw and havingaheado'r body portion and a stem portion forming. shoulder-with said 60being in engagement with the counterbore, one of said surfaces beingconical, whereby, upon relative movement of said nut towards said sleeveand said shoulder into engagement with the top of said sleeve, saidstemv grips said screwsufiiciently to prevent disturbance of the screwdue to motor vibrations, but not suf-f flciently to prevent adjustmentof the screw by means of a wrench.v JOHN A. NAHIJNGER.

a poppet valve, a tappet tappet screw, a adjusted position, 30 and meansfor normally concealing said nut en- 5 said cap being movableto uncoverhead 'or bodyfportion, the surface of said stem surface of said

